This invention relates to a method of making a net comprising at least one strand. The invention also relates to such a net. More specifically, the invention relates to a method of making a net comprising a plurality of strands of braided or plaited synthetic fibres, and to a net made by such a method.
Hitherto, nets have usually been formed by knotting the intersections between the netting strand portions. Such knotted nets entail inherent weakness at the knots.
In cases when the netting strand is of a synthetic plastics material, it is also known to form the intersections by welding. Welding of synthetic plastics netting strand portions often leads to weakness at the joints and must be performed with great care.
In order to overcome these disadvantages it has been suggested to form an intersection between two portions of the length of the netting strand by passing one such length portion through a hole formed in the other of them. Nets made in this way have the characteristic feature that their intersections can slip, thus leading to local enlargement of the mesh, unless special precautions are taken. This is a serious drawback in some fields of use. This suggestion has been made especially in the case of nets made from webbing, and one special precaution is often stitching the intersecting strand portions together.
The present invention has as its broad object to provide netting which is neither knotted nor welded at the intersections of strand portions. Furthermore, the intersections are not stitched. Thus, the present invention has as its broad object to provide netting which is neither knotted nor welded at the intersections of strand length portions and in which such intersections can constitute secure non-slip junctions.
As broadly defined, the present invention resides in a method of making a net using at least one strand, characterised in that strand portions are formed at at least one intersection by threading each of two strand portions through a hole in the other of them.
In other words, one form of the present invention provides a method of making a net using a plurality of intersecting strands of braided or plaited fibres which can be synthetic, wherein at at least one intersection there are two said strands which are joined together by providing a hole through the body of each of them, and threading a first one of said strands as a body through the hole in the second of said strands, arranging said strands so that the hole through said second strand is spaced apart from the hole in the first strand, angling each of said strands back on itself, threading said second strand as a body through the hole through said first strand, and drawing said strands together by pulling on said strands so that said strands contact each other in the area between said holes to form a secure non-slip junction between said two strands.
Therefore, as broadly defined, the present invention resides in a method of making a net using at least one strand, characterised in that strand length portions are joined at at least one intersection by threading the body of each of two strand length portions through a hole in the other of them.
Making a netting strand intersection in this way is simple and convenient. Such an intersection can be considerably stronger in certain directions than a knotted or welded net. Often, in such knotted or welded nets, the strands are of the same breaking strength. Furthermore, in a knotted net an amount of the netting strand or strands is used up to form the knots, so that by making use of the present invention, a reduction in the length of strand used results. A net intersection made in this way can constitute a secure non-slip junction.
A principal field of use of nets made in accordance with this invention lies in the field of air cargo nets, and it will be appreciated that weight is a particularly important feature in this field. In fact in certain knotted nets which would be of suitable strength for use in air transport, as much as 30% or even 65% of the weight of the net is taken up by the netting strand in the knots. By making use of the present invention, it is possible to reduce the amount of material actually involved in forming the intersections to less than 10% of the weight of the net.
A further important advantage follows from the above. Because of the bulk of material involved in forming knots, these knots project outwardly from any load held by the net, and the knots are thus apt to be abraded easily thus greatly shortening the useful life of a knotted net. This is not the case with a net made in accordance with the present invention to anything like the same extent, particularly when each intersection is formed in the specified "interthreaded" manner, as is preferred.
A said netting strand may be constituted by a strap which can be woven or not, or by twisted or hawser-laid cord.
Preferably, however, the or each said netting strand is braided or plaited cord. Braided or plaited cord is stronger weight for weight than hawser-laid cord, and enables a non-slip intersection to be made.
After completion of the net weaving process, the net may be impregnated with a binding agent to cause the synthetic fibres of each strand to cohere. This promotes the non-slip quality of the intersections, and has the further advantage of reducing abrasion of the strands of the net in use.
In certain embodiments of the invention, the netting strand is pre-formed with a plurality of holes therethrough in places appropriate for forming intersections in a net to be made therefrom, but in the most preferred embodiments of the invention, holes are made in the netting strand during the net making process. In this way, lengths of the same strand could be used to make nets of various differing mesh dimensions. Such holes could be made by hand, for example using a marling spike. Thus, in certain embodiments of the invention, the netting strand is preformed with a plurality of holes through the body thereof.
The invention also relates to a net, comprising at least one strand, and is characterised in that at at least the majority of strand intersections remote from the edge of the net, there are at least two intersecting netting strand portions and each of such two strand portions includes a hole through which the other of them passes.
Stated another way, the invention also relates to a net, comprising at least one strand, and is characterised in that at at least the majority of strand intersections remote from the edge of the net, there are at least two intersecting strand length portions and each of such strand length portions includes a hole through which the body of the other of them passes.
In preferred embodiments of net according to the invention, there is a border cord which extends around at least a part of the periphery of the net, and at at least some of the junctions between netting strand portions and such border cord, the border cord passes through a hole in a netting strand portion and the netting strand passes through a hole in the border cord.
It is noted that the netting strand portion and the border cord portion passing through the holes, each do so as a body.
In many cases it is not always necessary for all the strand-border junctions to be formed in this way; for example, the strand can simply be looped around the border cord. Nonetheless, a more secure junction is afforded when strand portions and the border cord pass through one another as described.
Preferably the or a said strand is of braided or plaited cord, and in the most preferred embodiments is formed from synthetic fibres, for example nylon.
In one net form, the strands pass from one side of the net to the other in unbroken zig-zag manner. This greatly increases the strength of the net in that side to side direction.
A net using the intersection embodying the present invention is formed in a one-piece cruciform shape with the cruciform having a center section or central panel section, with a plurality of wing sections, or side flaps, herein referred to as panel portions, or lobes, extending outwardly therefrom. It has been found that such a shape is very convenient for use in restraining loads on cargo pallets during transportation, although the net can be formed to be clipped onto a floor of an aircraft by appropriate attaching means.
Advantageously a tying cord is attached at at least one corner of said cruciform shape whereby when such net is placed over a rectangular load, each said tying cord can be interlaced through the borders of adjacent lobes of the net to close the net down that corner of the load.
As used herein, a re-entrant angle is a corner between adjacent lobes at the point of intersection between the lobes and the central panel section, and the tying cord can be attached to the net at one, or a plurality of, the net re-entrant angles.